Where on earth does Tango 123 get his figures from? Maybe he's listening to the voices in his head?
According to the FT, oil production costs per barrel in the North Sea have risen by 300% in the last 15 years and it now costs around $18 per barrel to lift.
To quote from the McKinsey report of 2014
North Sea oil and gas costs have risen faster than any other industrial sector in the region, causing projects to be shelved and activity postponed, and challenging the long-term viability of existing fields and infrastructure.
Decommissioning costs are increasing in a time of decreasing profits:
Low Oil Prices Throw Nort Sea into a Period of Crisis
If Iranian oil comes onto the market in the next 6 months as widely predicted, this will probably lead to an oil war between them and the Saudis, which will drive oil down to around $20 a barrel or even lower.